Question: Which borders of borders of Riverside have a start date of 1984-0-0?
Paraphrase: Which borders of borders of Riverside have a begin date of 1984-0-0?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q49243 wdt:P47 ?answer . ?answer wdt:P571 ?x FILTER(contains(YEAR(?x),'1984'))}
Answer: Moreno Valley